1. Field of the Invention
The present invention relates generally to a light diffusion module and a back light module using the same; particularly, the present invention relates to a light diffusion module applied in the liquid crystal display panel and a back light module using the same.
2. Description of the Prior Art
The back light module has been widely applied to liquid crystal display device, computer keyboard, mobile phone key, billboard, and other devices which need light source to provide the plain light source. Particularly, the market demands for the liquid crystal display device raise rapidly in recent years, the design of the back light module applied to the liquid crystal display device becomes versatile in order to fulfill the requirement of function and appearance.
However, when the back light module is applied to the liquid crystal display panel, the uniformity of the light emitted from the back light module plays a very important role that influences the overall efficiency of the liquid crystal display panel all the time. Especially, while the size of the liquid crystal display panel grows larger day by day, disposing the lamps of the module vertically downward has become a trendy development of the current back light module. How to uniformly diffuse the light emitted from the lamps juxtapositioned to each other and further preventing the condition of excessively bright or excessively dark in certain areas become an important topic in designing the liquid crystal display panel.
FIG. 1a shows a conventional structure to diffuse the light. As FIG. 1a shows, the back light module 10 includes a plurality of lamps 13 juxtapositioned to each other and a reflecting plate 15. There is a light controlling board 31 on top of the lamp 13, which functions as leading and controlling the path of the light. The light controlling board 31 has a diffusion plate 32, which further diffuses the light. On top of the diffusion plate 32 is a liquid crystal glass 50. After running through the light diffusion simulation of the prior art structure, the light diffusion effect is shown in FIG. 1b. However as the area within the dotted line in FIG. 1b shows, it may be seen that those areas where lamps disposed tend to have the phenomenon of light concentration, and the darker parts of the weaker luminance area has the continuity as well.